Substrate conveyor system

ABSTRACT

Embodiments of a vacuum conveyor system are provided herein. In one embodiment, apparatus for conveying a substrate includes a vacuum sleeve and a plurality of rollers disposed within the vacuum sleeve for supporting and transporting the substrate thereupon. The plurality of rollers is adapted to simultaneously support the substrate thereupon at a plurality of elevations. A leading edge of the substrate is supported at an elevation above an adjacent one of the plurality of rollers in the direction of travel.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit of U.S. Provisional Application Ser. No.60/689,621, entitled “Linear Vacuum Deposition System”, filed Jun. 10,2005, which is hereby incorporated by reference in its entirety. Thisapplication is additionally related to U.S. application Ser. No.(Unknown), entitled “Substrate Handling System”, filed herewith byWendell Blonigan, et al., and U.S. application Ser. No. (Unknown),entitled “Linear Vacuum Deposition System”, filed herewith by JohnWhite, et al., both of which are hereby incorporated by reference in itsentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to a substrateconveyor system.

2. Description of the Related Art

Glass substrates are being used to fabricate active matrix televisionand computer displays, or for solar panel applications, among others. Ina television or computer display application, each glass substrate canform multiple display monitors each of which contains more than amillion thin film transistors.

The processing of large glass substrates often involves the performanceof multiple sequential steps, including, for example, the performance ofchemical vapor deposition (CVD) processes, physical vapor deposition(PVD) processes, or etch processes. Systems for processing glasssubstrates can include one or more process chambers for performing thoseprocesses.

The glass substrates can have dimensions in the range of, for example,about 370 mm by 470 mm up to about 1870 mm by 2200 mm. Moreover, thetrend is toward even larger substrate sizes to allow more displays to beformed on the substrate or to allow larger displays to be produced. Thelarger sizes place even greater demands on the capabilities of theprocessing systems, which are growing in size and capability as well tohandle the larger substrates.

However, the current production equipment is getting more costly. Forexample, cluster tools suitable for vacuum processing of large glasssubstrates, e.g., 1 m² and larger, require a relatively large floorspace and are very costly. As such, the incremental cost of addingadditional equipment to the production line to increase throughput isvery expensive.

Therefore, there is a need for an improved system for processingsubstrates.

SUMMARY OF THE INVENTION

Embodiments of a vacuum conveyor system are provided herein. In oneembodiment, apparatus for conveying a substrate includes a vacuum sleeveand a plurality of rollers disposed within the vacuum sleeve forsupporting and transporting the substrate thereupon. The plurality ofrollers are adapted to simultaneously support the substrate thereupon ata plurality of elevations. A leading edge of the substrate is supportedat an elevation above an adjacent one of the plurality of rollers in thedirection of travel.

In another embodiment, apparatus for conveying a substrate includes avacuum sleeve and a plurality of eccentrically-shaped rollers disposedwithin the vacuum sleeve for supporting and transporting the substratethereupon. A first one of the plurality of rollers supports a leadingedge of the substrate at an elevation above an adjacent one of theplurality of rollers in the direction of travel.

In another embodiment, apparatus for conveying a substrate includes avacuum sleeve and a plurality of eccentrically-shaped driven rollersdisposed within the vacuum sleeve for supporting and transporting thesubstrate thereupon. The plurality of eccentrically-shaped drivenrollers are rotationally out of phase with respect to each other. Afirst one of the plurality of rollers supports a leading edge of thesubstrate at an elevation above an adjacent one of the plurality ofrollers in the direction of travel.

In another aspect of the invention, a method of conveying a substrate isprovided. In one embodiment, a method for conveying a substrate includesmoving a substrate on a plurality of rollers in a desired direction andraising a leading edge of the substrate with respect to an adjacentroller in the direction of travel.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1A is a top view of one embodiment of a vacuum conveyor system;

FIG. 1B is a partial side view of a vacuum conveyor system;

FIG. 2 is a top view of another embodiment of a vacuum conveyor system;

FIGS. 3A-B are partial top and side views, respectively, of a vacuumconveyor system detailing one embodiment of a substrate handler;

FIGS. 4A-B are partial top and side views, respectively, of a vacuumconveyor system detailing another embodiment of a substrate handler;

FIGS. 5A-B are schematic top and side views, respectively, of oneembodiment of a magnetic rack and pinion drive mechanism suitable foruse with embodiments of the substrate handler;

FIG. 5C is a bottom view of the magnetic pinion of the magnetic rack andpinion drive mechanism of FIGS. 5A-B;

FIG. 6A is a top view of one embodiment of a roller drive system of avacuum conveyor system;

FIG. 6B is a detail of one embodiment of a roller of a vacuum conveyorsystem;

FIGS. 7A-E depict various embodiments of roller configurations;

FIG. 8 is a top view of another embodiment of a substrate handler;

FIG. 9 is a schematic top view of another embodiment of a vacuumconveyor system;

FIG. 10 is a schematic top view of another embodiment of a vacuumconveyor system; and

FIG. 11 is a partial schematic side view of one embodiment of theplurality of rollers.

DETAILED DESCRIPTION

Embodiments of a vacuum conveyor system are provided herein. The vacuumconveyor system a sealed, sub-atmospheric pressure substrate transportsystem that may be coupled to a plurality of process chambers tofacilitate transfer of substrates between process chambers whileremaining at processing pressures, i.e., in a vacuum. The vacuumconveyor system may be connected to any load locks or process chambers,including conventional load locks and process chambers. The processchambers may be any process chambers that operate at a vacuum, such aschemical vapor deposition (CVD) chambers, physical vapor deposition(PVD) chambers, atomic layer deposition (ALD) chambers, or any otherdeposition or other processing chamber that operates at sub-atmosphericpressures.

FIG. 1A depicts a simplified top view of a vacuum conveyor system 100.The vacuum conveyor system 100 comprises a vacuum sleeve 102 having oneor more ports 108 and enclosing a plurality of rollers 104 and one ormore substrate handlers 106. The size of the vacuum sleeve 102 isminimized to provide the smallest possible volume necessary to allowsubstrate transport therethrough. The small volume facilitates moreeasily establishing and maintaining a vacuum within the vacuum sleeve102 and reduces the time required to pump the pressure down to thedesired level of vacuum. The smaller dimensions of the vacuum sleeve 102further increase the robustness of the vacuum conveyor system 100 bymaintaining a smaller volume of vacuum within the vacuum sleeve 102,thereby lessening the forces resultant from the pressure differentialbetween the low interior pressure and atmospheric pressure outside ofthe vacuum sleeve 102.

Optionally, and as depicted in FIG. 1B, one or more volume reducers 118may be provided to reduce the interior volume of the vacuum sleeve 102.The volume reducer may be a solid or hollow member, for example a hollowbox, that occupies space within, i.e., reduces the interior volume of,the vacuum sleeve 102. In one embodiment, the volume reducers 118 may bedisposed above the plurality of rollers 104 and between adjacent ports108. The volume reducers 118 are sized to not interfere with thetransport and handling of a substrate 190 supported on the plurality ofroller 104 or the substrate handlers 106. It is contemplated that volumereducers having any shape or size may be placed in any unobtrusivelocation within the vacuum sleeve 102 to further reduce the interiorvolume of the vacuum sleeve 102 that must be evacuated and maintained ata desired vacuum pressure.

Returning to FIG. 1A, determinant factors for the volume of the vacuumsleeve 102 include factors that affect the height, length, and width ofthe vacuum sleeve 102. For example, the height of the vacuum sleeve 102is constrained by the height of the plurality of rollers and the heightto which the substrate must be raised by the substrate handlers 106. Inone embodiment, the height of the vacuum sleeve is less than about 30inches. In another embodiment, the height of the vacuum sleeve 102 isless than about 20 inches. The length of the vacuum sleeve isconstrained by the number of process chambers 120 attached thereto andthe spacing between the process chambers. The width of the vacuum sleeve102 is constrained by the width of the substrate and the extra widthrequired for the lateral movement of the substrate by the substratehandlers 106.

The vacuum sleeve 102 has one or more ports 108 for sealably couplingthe vacuum sleeve 102 to one or more process chambers. The processchambers may be sealably coupled to the vacuum sleeve 102 in anysuitable manner and the process chambers may be mounted flush with thevacuum sleeve 102. In the embodiment depicted in FIG. 1A, four processchambers 120 ₁, 120 ₂, 120 ₃ and 120 _(n) are shown connected to thevacuum sleeve 102 of the vacuum conveyor system 100 at respective ports108. The ports 108 couple the vacuum sleeve 102 to the process chambersaround a corresponding aperture, e.g., a process chamber slit valve, tofacilitate transferring a substrate between the vacuum sleeve 102 andthe process chambers 120 ₁-120 _(n). Coupling the process chambers closeto the vacuum sleeve 102 minimizes the horizontal distance that asubstrate must move to be transferred by the substrate handlers 106 fromthe plurality of rollers 104 to the substrate support of the respectiveprocess chamber, thereby helping to minimize the volume of the vacuumsleeve 102.

Optionally, a connector 116 may be disposed between the vacuum sleeve102 and one or more of the process chambers. The connector 116 may be anadapter that facilitates mating the vacuum sleeve 102 with processchambers that are unable to be directly coupled to the vacuum sleeve102. Alternatively or in combination, the connector 116 may be a spacerfor positioning a process chamber in a desired location. For example,the connector 116 may be utilized to more accurately locate a substratesupport disposed within a process chamber at a desired distance from thevacuum sleeve 102 to facilitate alignment with the extended position ofa respective substrate handler 106.

The one or more substrate handlers 106 are dedicated to a particularprocess chamber and, as such, one substrate handler 106 is providedproximate each process chamber coupled to the vacuum sleeve, forexample, process chambers 120 _(1-n) coupled to the vacuum sleeve 102 inFIG. 1A. The substrate handlers 106 generally have an idle position thatdoes not interfere with the substrates traveling on the plurality ofrollers 104 through the vacuum sleeve 102, and at least a transferposition suitable for transferring substrates to and from the processchamber. As such, the substrate handlers 106 only need to have a rangeof vertical motion and a range of horizontal motion in a directiontowards and away from the process chambers, i.e., perpendicular to thelength of the vacuum sleeve 102, thereby being substantially lessexpensive than vacuum transfer robots having additional lateral and/orrotational degrees of freedom. It is contemplated that the position ofthe substrate handler 106 may controllably fixed at multiple locationswithin the vertical and horizontal ranges of motion.

Suitable sensors and control systems (not shown) for the substratehandlers 106 may be provided and integrated with a controller 150 thatcontrols the operation of the vacuum conveyor system 100. The sensorsand control systems may detect the position of a substrate on theplurality of rollers 104 and/or on the substrate handlers 106. Thesensors and control systems may further detect the position of thesubstrate handlers 106—and/or and substrate supported thereon—when thesubstrate handlers 106 are utilized to transfer a substrate into or froma respective process chamber.

FIGS. 3A and 3B respectively depict top and side views of one embodimentof the substrate handler 106. The substrate handler 106 generallyincludes a substantially flat surface for supporting a substratethereupon and is configured to travel between the plurality of rollers104. In one embodiment, the substrate handler 106 includes a bracket 302with a plurality of support fingers 304 extending horizontallytherefrom. The support fingers 304 are positioned between individualones of the plurality of rollers 104, and in retracted position, liebelow the height of the plurality of rollers 104, so as not to interferewith the motion of the substrate thereover.

The support fingers 304 of the substrate handler 106 are verticallypositioned by one or more vertical motion assemblies 306 coupled to thebracket 302. The vertical motion assemblies 306 may provide a range ofmotion that is infinitely controllable or controllable to discretepositions. In one embodiment, the pair of vertical motion assemblies 306each comprise a pair of vertically stacked actuators 340, 342 that eachhave an extended and a retracted position. Control of the actuators 340,342 allow for a retracted position 334 (both actuators retracted), atransfer position 332 (one actuator extended, the other retracted), anda raised position 330 (both actuators extended). The amount of extensionneeded will be dependent upon the distance between the retractedposition, the height of the bottom of a substrate 300 extended upon aset of lift pins 326 in a process chamber 120 _(n), and the height ofthe top of a slit valve 322 formed in a wall 320 of the process chamber120 _(n).

The vertical motion assemblies 306 may include any suitable actuator,such as a pneumatic or hydraulic actuator, screw, solenoid, motor, orany suitable actuator for providing the desired vertical motion of thesubstrate handler 106. In one embodiment, the actuators 340, 342 of thevertical motion assemblies 306 are sealed pneumatic actuators. Aflexible tube (not shown) may be run to an air source (not shown)disposed outside of the vacuum sleeve 102.

A controller 308 is provided to control the vertical actuation of thesubstrate handler 106. AC power from an AC power source 350 is providedthrough power line 352 to the controller 308. Control signals may beprovided through the AC power line by modulating the control signals atvarying frequencies. Thus, multiple substrate handlers 106 may beindependently controlled while being connected to the same power line352 and AC power source 350. The control signals may be provided by acontroller 150 (described below with respect to FIG. 1A).

A horizontal motion assembly 318 provides for horizontal movement of thesubstrate handler 106, e.g., the movement into and out of the processchambers. The horizontal motion assembly 318 may include any suitablemechanism such as pneumatic or hydraulic actuators, lead screws, motors,and the like. In one embodiment, the horizontal motion assembly 318includes a stage 312 movably coupled to a plurality of horizontal rails310. The stage 312 is coupled to the bottom of the vertical motionassemblies 306 such that movement of the stage 312 moves the bracket 302and support fingers 304. The horizontal rails 310 are disposed on abottom of the vacuum sleeve 102 substantially parallel to the pluralityof rollers 104 to facilitate horizontal movement towards and away fromthe process chamber.

An extension 316 is coupled to the stage 312 and projects through anopening formed in the vacuum sleeve 102. A tube 316 is coupled to thevacuum sleeve 102 around the opening to maintain vacuum integrity. Ano-ring or other sealing mechanism (not shown) may optionally be disposedbetween the tube 316 and the vacuum sleeve 102 to facilitate forming anair-tight seal. The tube 316 provides a sealed area long enough to allowthe extension 314 to move as required to control the horizontal positionof the substrate handler 106.

A drive mechanism 370 is coupled to the extension 314 through the tube316 to control the horizontal movement of the substrate handler 106. Thedrive mechanism 370 may further be controlled by the controller 150. Inone embodiment, the drive mechanism 370 may be a magnetic drive system.One example of a magnetic drive system suitable for use with the presentinvention is described in U.S. Pat. No. 6,471,459 issued Oct. 29, 2002to Blonigan, et al., and entitled, “Substrate Transfer Shuttle Having aMagnetic Drive,” which is hereby incorporated by reference.

FIGS. 5A-B are schematic top and side views, respectively, of oneembodiment of a magnetic rack and pinion drive mechanism suitable foruse with embodiments of the substrate handler. FIG. 5C is a bottom viewof the magnetic pinion of the magnetic rack and pinion drive mechanismof FIGS. 5A-B. Referring simultaneously to FIGS. 5A-C (certain elementsof the substrate processing system are not illustrated in FIGS. 5A-5Cfor the sake of clarity), each magnetic drive mechanism, e.g., drivemechanism 590, includes a wheel-shaped magnetic pinion 592 positionedbeneath the tube 316 containing the extension 314 of the substratehandler 106. At least a portion of the extension 314 comprises amagnetic rack 548 corresponding to the magnetic pinion 592. A flange 542may be formed on one or both sides of the rack 548 and one or morerotating supports 582, 584 may be positioned to support the rack 548 andprevent sagging due to gravity or the magnetic coupling to the pinion592.

The magnetic pinion 592 may be positioned beneath an associated tube 316so that it is located outside the processing environment but positioneddirectly beneath one of the magnetic racks 548. The magnetic pinion 592is thus separated from the magnetic rack 548 by a gap having a width, w,(see FIG. 5B). The portion of the tube 316 disposed between the magneticrack 548 and the magnetic pinion 592 is formed of a material having alow magnetic permeability, such as aluminum.

Each magnetic pinion 592 may be coupled to a motor 594 by a drive shaft596. The axis of rotation (shown by dashed line 98) of the drive shaft596 and the magnetic pinion 592 is generally perpendicular to thelongitudinal dimension of the magnetic rack 548, i.e., perpendicular tothe direction of travel of the substrate handler 106.

Each magnetic pinion 592 includes a plurality of interleaved pinionmagnets 500 a and 500 b of alternating polarity. Each pinion magnet isaligned so that its magnetic axis passes substantially through the axisof rotation 598 of the magnetic pinion 592. Similarly, each rack 548includes a plurality of interleaved rack magnets 510 a and 510 b ofalternating polarity. The magnetic axis of each rack magnet is alignedsubstantially perpendicular to the axis of rotation of the pinion, e.g.,along a vertical axis 524 if the axis of rotation is substantiallyhorizontal. The rack magnets 510 a and 510 b may be recessed so thatthey are flush with the bottom surface of the rack 548, and the pinionmagnets may be recessed so that they are flush with the outer rim of thepinion 592.

Each magnet in the rack 548 and the pinion 592 may be a substantiallyrectangular plate which is magnetized so that there is a north pole “N”at one face of the plate and a south pole “S” at the opposite face ofthe plate. For example, pinion magnets 500 a are oriented with theirnorth poles at exterior faces 502 of the plates and their south poles atinterior faces 504 of the plates. On the other hand, pinion magnets 500b are oriented with their north poles at interior faces 504 of the plateand their south poles at exterior faces 502 of the plates. Similarly,each rack magnet 510 a is oriented with a north pole at an upper face514 of the plate and a south pole at a lower face 512 of the plate.Conversely, each rack magnet 510 b is oriented with a north pole at thelower face 512 of the plate and a south pole at the upper face 514 ofthe plate.

As shown in FIG. 5A, a primary axis of each rack magnet plate (shown bydashed line 508) may be arranged with a so-called “helix” angle αbetween the axis of rotation 598 and the primary axis 508. As shown inFIG. 5C, the pinion magnet plates may be arranged with the same helixangle α′, between the axis of rotation 598 of the pinion 592 and theprimary axis 508′ of the pinion magnets. The helix angle may be up toabout 45 degrees. Alternately, the primary axis of each magnet may beoriented generally parallel to the axis of rotation 98 of the pinion(α=0 degrees). Thus, the helix angle may be between about 0 and 45degrees. By positioning the magnets at a helix angle, the variations inthe magnetic attraction forces between the rack and pinion magnets astheir magnetic fields engage and disengage are reduced, therebyproviding a smoother linear motion of the substrate handler 106. Ineither case, at the closest point of approach, the pinion magnet will besubstantially coplanar with its associated rack magnet.

The pinion magnets 500 a and 500 b are separated by a pitch P, which isequal to the pitch P′ of the rack magnets 510 a and 510 b. The pitches Pand P′ may be about ¼ inch. The specific pitch may be selected based onthe strength of the magnets, the weight of the substrate handler and anysubstrate to be supported thereupon, the width W of the gap between therack and pinion, and the desired speed at which the substrate handlerwill move between the sleeve 102 and the respective process chamber.

As best shown in FIG. 5B, the rack and pinion magnets engage as theiropposing poles lock together (shown by lines of magnetic force 518). Ifthe pinion 592 is rotating, then as each pinion magnet, e.g., pinionmagnet 500 a, moves toward the rack 548, it will magnetically couplewith the closest magnet of opposing polarity, e.g., rack magnet 510 a.In addition, the adjacent pinion magnets 500 b (of opposite polarity aspinion magnet 500 a) will be magnetically coupled to the adjacent rackmagnets 510 b. Thus, as the pinion 592 rotates, e.g., in the directionshown by arrow 506, the substrate handler 106 will be drivenhorizontally, i.e., in the direction shown by arrow 516. Conversely, ifthe pinion 592 rotates in a direction opposite to arrow 506, thesubstrate handler 106 will be driven in a direction opposite to arrow516.

The alternating polarity of the magnets prevents magnetic couplingslippage between adjacent magnets in the rack and pinion. Also, sincethe engagement between the rack and pinion is magnetic, there is aslight give in the coupling, so that the motion of the rack issubstantially without jittering or mechanical shock. Furthermore, sincethere are no rotary feedthroughs or direct physical contact between therack and pinion, the danger of contamination from the drive mechanism isreduced. Specifically, since the motor and pinion are located outsidethe processing environment of the chambers (i.e., the sealed environmentof the vacuum conveyor system and the attached processing chambers andload lock chambers), the processing chambers and load lock chambersshould not be contaminated.

As shown in FIG. 5C, each drive mechanism may include an encoder 520which provides input to a control system 522, e.g., a general purposeprogrammable digital computer, to indicate the rotation of theassociated drive shaft. The control system 522 may be the controlled by,or alternatively may be a part of, the controller 150 depicted in FIG.1A.

Returning to FIGS. 3A-B, in operation, the substrate handler 106 isinitially in the idle position 354, wherein the fingers 304 are disposedbelow and in between the rollers 104. To remove a substrate that may bein a process chamber 120 _(n), the controller raises the vertical motionassemblies 306 to elevate the fingers 304 to the transfer position 332.The horizontal drive system 370 then engages the extension 314 of thehorizontal motion assembly 318 to move the stage 312 inward toward theprocessing chamber 120 _(n). The substrate 300 is raised by the liftpins 326 on the substrate support 324 disposed within the processchamber 120 _(n). The fingers 304 of the substrate handler 106 in thetransfer position 332 are at a height that allows the fingers 304 topass between the bottom surface of the substrate 300 and the top surfaceof substrate support 324. After moving underneath the substrate 300, thesubstrate handler 106 is further actuated to the raised position 330,which lifts the substrate 300 off the lift pins 326. The substratehandler 106 may now retract with the substrate 300 and, once clear ofthe process chamber 120 _(n), may lower back to the idle position 334,which will dispose the substrate 300 on the surface of the rollers 104.A substrate may be placed onto the substrate support 324 of the processchamber 120 _(n) by reversing the above steps.

It is contemplated that other ranges of motion may be utilized totransfer substrates into and out of the process chambers. For example,where the substrate lift pins 326 are controllable to multiple extendedpositions, the substrate may be lifted off of or placed onto thesubstrate handler 106 by raising or lowering the lift pins 326 ratherthan by changing the elevation of the substrate handler 106. As such,certain embodiments of the substrate handler 106 may have only twovertical positions, and idle position below the plurality of rollers 104and a transfer position suitable for entering and exiting the processchamber 120 _(n).

FIGS. 4A and 4B respectively depict top and side views of anotherembodiment of a substrate handler 106 having a pair of nested fingersthat independently operate to move substrates into and out of theprocess chamber to increase process throughput. The substrate handler106 described with respect to FIGS. 4A-B is similar to the substratehandler 106 described with respect to FIGS. 3A-B with the exceptionsrequired to allow independent control and movement of the nestedfingers. Specifically, the substrate handler described with respect toFIGS. 3A-B and 4A-B may have the same ranges of motion, controlmechanisms, and general configuration.

In the embodiment depicted in FIGS. 4A-B, the substrate handler 106comprises an outer substrate handler 490 and an inner substrate handler492. The outer an inner substrate handlers 490, 492 are independentlycontrollable and configured to allow the desired ranges of motion of thesubstrate handlers 490, 492 without collision. The outer and innersubstrate handlers 490, 492 are similar except as where noted below.

The outer substrate handler 490 includes an outer bracket 402 having aplurality of outer fingers 404 extending horizontally therefrom. Theouter bracket 402 is held in vertical position by a pair of verticalmotion assemblies 406. The vertical motion assemblies 406 may optionallybe spaced wider than the length of a substrate to facilitate horizontalmovement when a substrate is disposed on the plurality of roller 104between the outer substrate handler 490 and the process chamber 120_(n). The vertical motion assemblies 406 may comprise a pair of stackedvertical actuators 440, 442. The vertical motion assemblies 406 (orvertical actuators 440, 442) are controlled by a controller 408. Thecontroller 408 is coupled to an AC power source 450 by a power line 452and controls the outer substrate handler 490 as described above withrespect to FIGS. 3A-B.

The vertical motion assemblies 406 are coupled to a horizontal motionassembly 418. The horizontal motion assembly 418 includes a stage 412,which is movably coupled to a plurality of horizontal rails 410 thatfacilitate movement of the outer substrate handler 490 into and out of aslit valve 422, formed in a wall 420 of the process chamber 120 _(n). Anextension 414 is coupled to the stage 412 and extends through an openingin the vacuum sleeve 102 horizontally in a direction toward andunderneath the process chamber 120 _(n). A tube 416 is provided tomaintain the vacuum integrity of the vacuum sleeve 102. A horizontaldrive system 470 is coupled to the extension 414 for providinghorizontal movement of the outer substrate handler 490. The horizontaldrive system 470 may be the same as described with respect to FIGS. 3A-Band 5A-C.

The inner substrate handler 492 includes an inner bracket 482 havinginner fingers 484 extending horizontally therefrom. The bracket 482 isheld in position by a pair of vertical motion assemblies 486. Thevertical motion assemblies 486 may comprise a pair of stacked verticalactuators (not shown for clarity). The vertical motion assemblies 486(or stacked vertical actuators) are controlled by a controller 488. Thecontroller 488 is coupled to the AC power source 450 through the powerline 452. Alternatively, the controller 408 may independently controlboth of the inner and outer substrate handlers 490, 492. Thusindependent control of the outer substrate handler 490 and the innersubstrate handler 492 may be provided utilizing the same power line andpower source. The bracket 482 and the fingers 484 of the inner substratehandler 492 may be disposed beneath the bracket 402 and the fingers 404of the outer substrate handler 490 to conserve space and minimize thewidth of the vacuum sleeve 102 required to house the substrate handlers490, 492.

Although not shown for clarity, the horizontal movement of the innersubstrate handler 492 on a horizontal motion assembly 498 having aplurality of horizontal rails 480 is controlled in the same manner asthe outer substrate handler 490. The plurality of horizontal rails 480that support the inner substrate handler 492 are provided in a positioninterior of the plurality of horizontal rails 410 that support the outersubstrate handler 490 to facilitate independent movement and control ofthe inner and outer substrate handlers 490, 492.

In operation, substrates may more efficiently be transferred to and fromthe process chamber 120 _(n) by elevating the outer substrate handler490 to a transfer position to pick up the substrate 400A from within theprocess chamber 120 _(n). As the outer substrate handler 490 is pickingup substrate 400A, substrate 400B arrives on the plurality of rollers104 in front of the process chamber 120 _(n). The inner substratehandler 492 then raises the substrate 400B and moves into the processchamber 120 _(n). This may be done while the outer substrate handler 490is simultaneously withdrawing with the substrate 400A just retrievedfrom the process chamber 120 _(n). The inner substrate handler 492 maythen lower the substrate 400B onto the lift pins 426 of the processchamber 120 _(n) and then retract from the process chamber 120 _(n). Theinner substrate handler 492 may then be lowered to the idle positionbelow the plurality of rollers 104 to allow the outer substrate handler490 to lower the substrate 400A onto the plurality of rollers 104 tocomplete the transfer.

Although described with respect to a vacuum conveyor system, it iscontemplated that the substrate handler described in FIGS. 3A-B and thenested substrate handler described in FIGS. 4A-B may be utilized inother systems requiring substrate conveying and transfer.

Returning to FIG. 1A, the plurality of rollers 104 facilitate movementof substrates through the vacuum sleeve 102. In one embodiment, theplurality of rollers 104 are driven to control the position of asubstrate disposed thereupon. The plurality of rollers 104 may be drivenand controlled by any suitable means and may be “gang” driven (i.e., alldriven in concert), driven in independently controllable groups, orindependently driven.

For example, FIG. 6A depicts one embodiment of the plurality of rollers104 and a drive system therefor. In one embodiment, the plurality ofrollers 104 comprise a plurality of rollers 624 coupled between bearings604, 606 disposed at either end of the roller 624. The bearing 606 iscoupled to a stanchion 608 that rests on the bottom of the vacuum sleeve102. Bearing 604 is coupled to a drive rail 602 disposed within thevacuum sleeve 102. A pulley 612 is coupled to each of the rollers 624and interfaces with a belt 610 that controls the motion of the rollers624. The pulleys 612 may also be provided between the rollers 624 tomaintain a proper interface between the pulleys 612 and the belt 610.One or more of the pulleys 612 may further have a feature, such asgrooves or notches 614 to interface with features formed on the belt(for example, V notches or square teeth formed on the belt) to improvetraction between the pulley 612 and the belt 610, and to preventslippage therebetween. A motor 630 may be provided to control the motionof the belt 610, and thereby the rollers 624. The motor 630 may becoupled to the controller 150 (shown in FIG. 1A). Each of the rollers624 may be controlled by a single motor 630. Alternatively, the rollers624 may be grouped to provide independent control over substratestraveling in specified regions of the conveyor system.

The rollers 624 may generally comprise a solid or hollow member.Moreover, the width of the rollers 624 may be wide enough to support thesubstrate thereupon using a single roller 624. Alternatively, thesubstrate may be supported at multiple points along the width of thesubstrate. For example, a single roller 624 may be “scalloped” or shaped(not shown) or, as shown in the detail of FIG. 6B, smaller individualrollers 622 disposed on an axis 620 may be utilized to support thesubstrate at multiple spaced-apart locations, thereby reducing thesurface contact area between the plurality of rollers 104 and thesubstrate. The reduced surface contact area reduces the likelihood ofparticle generation or damage to the substrate caused by contact betweenthe substrate and the plurality of rollers 104.

The rollers 104 are generally spaced close enough to each other toprovide adequate support for the substrates being handled to preventdeformation or damage of the substrate. One problem that may arise fromsuch deformation of the substrate is that a leading edge of thesubstrate may deflect downward due to gravity and come into contact withthe subsequent roller of the vacuum conveyer system 100, therebypotentially causing damage to the substrate and/or the roller. Forexample, the leading edge of the substrate may become chipped orfractured upon forceful contact with a subsequent roller. In addition,particles generated by the damage to the substrate or by scrapingagainst the subsequent roller may further damage the substrate. Thiseffect may be exacerbated by the high processing temperatures requiredin certain processes, which may cause the substrate—particularly a glasssubstrate—to soften and deflect further downwards.

FIGS. 7A through 7C depict embodiments showing various alignments of theplurality of rollers 104. In FIG. 7A, the plurality of rollers 104 areall aligned along a horizontal plane and rotate about an axis 704A, suchthat the substrate 700 rests flat on the surface of the plurality ofrollers 104. As the substrate 700 moves from left to right, as indicatedby the arrow, a leading edge 702 of the substrate 700 extends pastroller 710A, and becomes unsupported until the leading edge 702 reachesroller 712A as the substrate 700 continues to move forward. Forapplications where the substrate does not appreciably deflect, thearrangement of the plurality of rollers 104 depicted in FIG. 7A may besufficient. However, if the leading edge 702 of the substrate 700deflects downward while unsupported between rollers 710A and 712A, theleading edge 702 may come into contact with roller 712A, potentiallydamaging the substrate 700.

Alternately, the plurality of rollers may be configured to support thesubstrate in a manner that compensates for any potential sag in theleading edge of the substrate by supporting the substrate in a mannerthat positions the leading edge of the substrate above any subsequentrollers as the substrate travels along the plurality of rollers. Forexample, In one embodiment, the plurality of rollers 104 may be arrangedas shown in FIG. 7B, wherein the plurality of rollers 104 compriseeccentric, or cam-shaped rollers. The eccentric rollers support thesubstrate 700 at a plurality of elevations due to the non-circularprofile of the rollers. The eccentric rollers rotate about an axis 706Band may be aligned with respect to one another. Alternatively, theeccentric rollers may be arranged rotationally out of phase with respectto one another such that a plurality of support elevations are providedbeneath a given substrate being supported by a subset of the pluralityof rollers disposed beneath the substrate.

For example, as depicted in FIG. 7B, the eccentric rollers may bealternatingly arranged 180 degrees out of phase, such that every otherroller (e.g., rollers 706B, 710B) is aligned with each other, and 180degrees out of phase with the adjacent rollers (e.g., 708B, 712B). Theeccentric shape of the rollers provide a plurality of support elevationsfor the substrate 700 between a first support elevation, for example,the maximum elevation when the eccentricity is pointing upwards, and asecond support elevation, for example, the minimum elevation when theeccentricity is pointing downwards. As the substrate 700 moves from leftto right, the leading edge 702 will be raised by the roller 710B,thereby compensating for any downward deflection that may occur to theleading edge 702 in the unsupported region between roller 710B and 712B.As such, when the substrate 700 comes into contact with the roller 712B,the leading edge 702 will not forcibly come into contact with the roller712B. The shape and amount of eccentricity of the roller 704B may becontrolled to provide smooth transport of the substrate 700.

In addition, the position of the substrate 700 when initially placed onthe rollers 704B may be controlled in conjunction with the relativerotational position of the rollers 704B, such that the leading edge 702of the substrate 700 will always exit and extend from the high portionof a roller as it moves toward an adjacent roller, as shown in FIG. 7B.Alternatively, and as shown in FIG. 7C, the plurality of rollers 104 maycomprise cylindrical rollers mounted on an offset axis 704C and disposedeccentrically in an alternating fashion to provide the same raising andlowering effect of the substrate 700, as described above with respect toFIG. 7B.

It is contemplated that other orientations of eccentric rollers may alsobe suitably utilized to prevent the leading edge of the substrate fromcontacting a subsequent roller as the substrate traverses the pluralityof rollers. For example, FIG. 7D depicts a plurality of rollers 104similar to those described with respect to FIG. 7B, above. However, inthis embodiment, the eccentric rollers are sequentially out of phasewith respect to each other by illustrative 90 degree increments in acounter-clockwise direction. A roller 706D is depicted with theeccentricity facing downwards. Each subsequent roller (rollers 708D,710D, and 712D, respectively) have the eccentricity extending in adirection 90 degrees counter-clockwise from the previous roller.

The quantity of offset of the eccentricity of the rollers, i.e.,rotational degrees out of phase, may be set to a desired angle dependingon the spacing of the rollers, the amount of eccentricity of therollers, and the amount of downward deflection of the substrate. It iscontemplated that the quantity of degrees out of phase of the rollers isnot limited to 180 and 90 degrees but may be any angle suitable toprevent the leading edge of the substrate from forcefully contacting aroller.

It is further contemplated that the shape of the eccentric roller is notlimited to a single protrusion as depicted in FIGS. 7B and 7D. Forexample, a roller having any desired profile including single ormultiple protrusions may be utilized to control the support elevationsof a substrate supported thereon as the roller rotates. In oneillustrative embodiment, the plurality of rollers 104 may comprise ovalrollers 706E, 708E, 710E, 712E. The oval shape of the rollers may beused to control the support elevation of the substrate 700, andparticularly of the leading edge 702 of the substrate, as the substratetraverses, for example, from a leading roller 710E to a subsequentroller 712E.

It is further contemplated that other configurations of the plurality ofrollers 104 may be utilized to compensate for any sagging of the leadingedge of the substrate, such as configurations that control the height ofthe rollers or that provide a separate mechanism for supporting theleading edge of the substrate. For example, FIG. 11 depicts a partialschematic side view of one embodiment of the plurality of rollers 104.In one embodiment, each of the plurality of rollers 104 may be coupledto an actuator 1102. The actuators 1102 may be any suitable actuator ormechanism for controlling the support elevation of the plurality ofrollers 104, such as pneumatic or hydraulic actuators, motors, screws,and the like. Each actuator 1102 may be individually controlled toselectively and dynamically adjust the position of any of the pluralityof rollers 104 with respect to each other as the substrate traverses theplurality of rollers 104. For example, in the embodiment depicted inFIG. 11, the leading edge 702 of the substrate 704 is supported by aroller 1110 that is raised at least with respect to a subsequent roller1112. Alternatively or in combination, the subsequent roller in thedirection of travel, e.g., roller 1112, may be lowered, as shown inphantom, to further facilitate the smooth transition of the leading edge702 to the roller 1112. Although described in FIGS. 7B-E and FIG. 11 asincorporated into a vacuum conveyor system, it is contemplated that theroller configurations described may be utilized in other conveying andprocessing systems where compensation for any sag of the leading edge ofa substrate is desired.

Returning to FIG. 1A, a load lock 110 is coupled to the vacuum sleeve102 at each of a first end 112 and a second end 114 of the vacuum sleeve102. A pressure control system (not shown), including pumps, ports,valves, meters, and the like, may be coupled to the vacuum sleeve 102 tocontrol the pressure within the vacuum sleeve 102 at a desired level.For example, the pressure in the vacuum sleeve 102 may be maintained ator near the pressure as is maintained within the process chambers tominimize changes in pressure upon transferring substrates between thevacuum sleeve 102 and the process chambers, thereby conserving the timerequired to re-adjust the chamber pressures to appropriate processinglevels and further minimizing contamination of the process chamber byany particles that may be carried into the process chamber due to anincrease in the chamber pressure.

A controller 150 is provided to facilitate control and integration ofthe vacuum conveyor system 100. The controller 150 typically comprises acentral processing unit (CPU), memory, and support circuits (not shown).The controller 150 may be coupled to various components of the vacuumconveyor system 100 in order to control movement and/or processing ofthe substrate. For example, the controller 150 may control the pluralityof rollers 104, the substrate handlers 106, the pressure control system,and the like. The controller 150 may be coupled to or may be the same asa controller provided to control other components such as any load locksand/or process chambers coupled to the vacuum conveyor system 100.

FIG. 2 discloses another embodiment of a vacuum conveyor system 200. Thevacuum conveyor system 200 is similar to the vacuum conveyor system 100described above with respect to FIG. 1A, except that the vacuum conveyorsystem 200 has two vacuum sleeves 102 running parallel to each other.The two vacuum sleeves 102 have one or more process chambers 220disposed therebetween and sealably coupled to the vacuum sleeves 102 byrespective connectors 116.

The vacuum conveyor system 200 having two vacuum sleeves 102 facilitatesincreased processing throughput. The two vacuum sleeves 102 alsofacilitate continued processing in the event of a failure of one of thevacuum sleeves. Optionally, the vacuum sleeves 102 may be selectivelyisolatable from each other, for example by a valve or other suitablemechanism, to allow continued processing through the operable vacuumsleeve without maintaining a vacuum in the inoperable vacuum sleeve. Inaddition, maintenance or inspection of the inoperable vacuum sleeve maybe performed while continuing to process substrates through the operablevacuum sleeve.

The process chambers 220 utilized with the vacuum conveyor system 200have a pass-through design, i.e., they have slit valves located onopposing sides of the process chamber 220, allowing a substrate to enteron one side of the process chamber 220 and exit on an opposite side ofthe process chamber 220. As such, substrate handlers 106 are provided onboth sides of the process chamber 220 to facilitate moving the substrateinto and out of the process chamber 220 at either end. In oneembodiment, the substrate handlers 106 may be the substrate handlerdescribed herein with respect to FIGS. 3A-B. Alternatively, thesubstrate handlers 106 may comprise the nested substrate handlers asdescribed with respect to FIGS. 4A-B.

A connector sleeve 202 is coupled between at least one end of the vacuumsleeves 102 to facilitate moving substrates from one vacuum sleeve 102to the other without going through the process chambers 220. Theconnector sleeve 202 contains a plurality of rollers 204 to facilitatemoving the substrate through the connector sleeve 202. The plurality ofrollers 204 may be configured similarly to the plurality of rollers 104.In one embodiment, the plurality of rollers 204 are configured similarto the plurality of rollers described in FIGS. 6A-B.

In the embodiment depicted in FIG. 2, two connector sleeves 202 arecoupled between the vacuum sleeves 102, one connector sleeve 202 ateither end. Although any angle is contemplated, the connector sleeves202 are substantially perpendicularly coupled to the vacuum sleeves 102for ease of fabrication and operation. A substrate handler 206 isprovided at least at one of the interfaces between vacuum sleeves 102and connector sleeves 202 to facilitate moving the substrate between therollers 104 in the vacuum sleeves 102 and the rollers 204 in theconnector sleeve 202. In the embodiment depicted in FIG. 2, onesubstrate handler 206 is provided at each interface between vacuumsleeves 102 and connector sleeves 202, e.g., at each corner of thevacuum conveyor system 200.

FIG. 8 depicts one embodiment of a substrate handler 206 fortransferring substrates between the plurality of rollers 104 containedin the vacuum sleeve 102 and the plurality of rollers 204 contained inthe connector sleeve 202, as shown in the corners of the vacuumconveying system 200 depicted in FIG. 2. In one embodiment, a substratehandler 806 is configured and positioned in the vacuum sleeve 102similar to substrate handler 106 described with respect to FIGS. 3A and3B. However, instead of extending and retracting the substrate into theprocess chamber, the substrate handler 806 extends and retracts totransfer the substrate onto a plurality of lift pins 810 providedbetween the plurality of rollers 204 of the connector sleeve 202.

In operation, as the substrate passes over the substrate handler 806while in retracted position 820, the substrate handler 806 may rise upto lift the substrate off of the plurality of rollers 104 and move to anextended position 822 disposed over plurality of rollers 204 and liftpins 810. From the extended position 822, the substrate handler 806 maythen lower the substrate onto lift pins 810 and proceed back to theretracted position 820. Alternatively, the lift pins may be configuredto extend to a height that facilitates lifting the substrate off of thesubstrate handler 806, which may then proceed to the retracted position820. The lift pins 810 may then lower the substrate onto the pluralityof rollers 204, which then move the substrate to the next desireddestination.

Referring to FIGS. 1 and 2, the vacuum conveyor system disclosed hereinis scalable and may be coupled to as few or as many process chambers asrequired for particular processing requirements. For example, the lengthof the vacuum sleeves 102 and the number of ports 108 provided may betailored for a particular application. In addition, the vacuum conveyorsystem may be segmented to facilitate scalability. For example, asegment could be the width of a single process chamber. Multiplesegments may be sealably coupled together as desired to form a vacuumconveying system of the desired length to service the desired number ofprocess chambers.

Alternatively, where known numbers of process chambers are used incombination to perform standard processes on substrates, the segmentsmay be larger in order to reduce the number of components, the amount ofwork needed to seal the chambers together, and the likelihood of leaks,thereby making the vacuum conveyor system more simple and robust. Forexample, in applications where a cluster of five CVD chambers aretypically provided to perform processing of a substrate, a segment ofthe vacuum conveying system vacuum sleeve 102 may be five processchambers in width, rather than piecing together five single-chamberwidth segments.

Furthermore, the vacuum conveyor system may be modular to separatesections utilizing different processes or operating at differentpressures. For example, a first module may comprise a first group ofprocess chambers and a second module may comprise a second group ofprocess chambers. The first group and the second group of processchambers may be running processes having different operating pressures.For example, the first group of process chambers may comprise CVDchambers and the second group of chambers may comprise PVD chambers. Thetwo modules may be independently configured as any of the embodiments ofvacuum conveyor systems described herein and may be coupled via a loadlock to allow transfer between modules without exposing either thesubstrate or the vacuum conveyor system modules to atmospheric pressure.

For example, FIG. 9 depicts a vacuum conveying system 900 having a firstvacuum conveying module 950 ₁ coupled to a second vacuum conveyingmodule 950 _(n) by a load lock chamber 110. Additional load lockchambers 110 are provided at either end of the first and second vacuumconveying modules 950 ₁ and 950 n to provide entrance to and egress fromthe vacuum conveying system 900. The first vacuum conveying module 950 ₁comprises a vacuum sleeve 902 having rollers 904 and substrate handlers906 contained therein. A connector 908 is provided to interface with oneor more process chambers 920 ₁ through 920 _(n). A dedicated substratehandler 906 is provided for each process chamber. The second vacuumconveyor module 950 _(n) similarly comprises a vacuum sleeve 912 havingrollers 914 and substrate handlers 916 disposed therein, and interfaceswith one or more process chambers 930 ₁ through 930 _(n). A dedicatedsubstrate handler 916 is provided for each process chamber 930 _(n). Thevacuum sleeves, plurality of rollers, and substrate handlers maycomprise any of the embodiments described herein and further include allother components required to operate the vacuum conveyor system, such asthe vacuum pumps, controllers, and the like.

As the first and the second vacuum conveyor modules 950 ₁ and 950 _(n)are sealed from each other via load lock 110, they may be held atdifferent levels of vacuum. For example, where process chambers 920 ₁through 920 _(n) are running a process utilizing a different level ofvacuum than process chambers 930 ₁ and 930 _(n), the first and secondvacuum conveyor modules 950 ₁ and 950 _(n) may be held at respectivevacuum levels correlating to the vacuum level of the particular processchambers connected to that vacuum conveyor module. For example, CVDprocesses generally operate at a higher pressure than PVD processes. Assuch, the process chambers 920 ₁ through 920 _(n) may be a cluster ofCVD chambers separated by the load lock 110 from the process chambers930 ₁ through 930 _(n), which may be a cluster of PVD process chambers.In this example, the pressure maintained in the vacuum conveyor module950 ₁ may be substantially equal to the pressure maintained in the CVDprocess chambers 920 ₁ through 920 _(n), while the pressure maintainedin the vacuum conveyor module 950 _(n) may be substantially equal to thelower pressure maintained in the PVD process chambers 930 ₁ through 930_(n).

FIG. 10 depicts one specific embodiment of a system of a hybrid CVD/PVDprocessing system 1000. The system 1000 generally comprises a firstvacuum conveyor module 1010 coupled to a second vacuum conveyor module1020 through a load lock 110. Additional load locks 110 are provided atthe opposing ends of the vacuum conveyor modules 1010 and 1020 toprovide entrance to and egress from the vacuum conveyor modules 1020 and1020. In the embodiment depicted in FIG. 10, an atmospheric conveyor1002 is coupled to the first module 1010 via the load lock 110. Theatmospheric conveyor 1002 allows coupling to processing chambers that donot operate at a vacuum. For example, in one embodiment, a plurality ofprocess chambers 1008 are coupled to the atmospheric conveyor 1002 forprocessing substrates prior to entering the vacuum conveyor system 1000.Process chambers 1008 may be, for example, pre-deposition cleaningchambers. In one embodiment, the pre-deposition cleaning chambers eachrun a sixty-second process having an eight-second transfer time,yielding a sixty-eight second total actual cycle time (TACT). Thesixty-eight second TACT corresponds to the fifty-two substrates per hourhandled by each process chamber 1008. In the embodiment depicted in FIG.10, three pre-deposition cleaning chambers 1008 are provided and may runin parallel to provide a total substrate throughput of 156 substratesper hour.

As each substrate is finished being processed, it is transferred throughthe load lock 110 to the first vacuum conveyor module 1010, which isheld at a first vacuum pressure. The first vacuum conveyor module 1010comprises a vacuum conveyor 1012 and a plurality of process chambers1014. The vacuum conveyor 1012 is similar to the vacuum conveyor systemsdescribed in the various embodiments detailed above. In the embodimentdepicted in FIG. 10, twenty process chambers 1014 are disposed withinthe first vacuum conveyor module 1010. In one embodiment, the processchambers 1014 are CVD process chambers. The CVD chambers may beconfigured to perform various processes, such as depositing a gatesilicone nitride layer, amorphous silicone layer, and a doped siliconelayer. These processes each may be performed in the same or differentprocess chamber 1014, at a throughput of six substrates per hour perchamber. Multiplied by twenty chambers, the total throughput for thefirst vacuum conveyor module 1010 equals 120 substrates per hour.

Once the substrates are finished being processed within the first vacuumconveyor module 1010, they proceed through the vacuum conveyor 1012 toload lock 110 and into the second vacuum conveyor module 1020. Thesecond vacuum conveyor module 1020 comprises a vacuum conveyor 1022, aspreviously described, and a plurality of process chambers 1024. In oneembodiment, six process chambers 1024 are provided. The process chambers1024 in the second module may be PVD chambers, which operate at a highervacuum level than the CVD chambers of the first module. As such, thevacuum conveyor 1022 of the second vacuum conveyor module 1020 ismaintained at a higher level of vacuum than the vacuum conveyor 1012 ofthe first vacuum conveyor module 1010.

The PVD chambers 1024 may be arranged to perform various vacuumprocesses on the substrate. In one embodiment, two of the processchambers 1024 are configured to deposit a layer of molybdenum on thesubstrate. For example, a 1,000-angstrom thick layer of molybdenum maybe deposited on the substrate at a rate of approximately 2,500 angstromsper minute. Such a process generally has a twenty-four second processtime, ten seconds of overhead, and an eight second transfer time,yielding a 42 second TACT. The 42 second TACT corresponds to 85substrates per hour in each chamber, yielding a total substratethroughput for the two chambers of 170 substrates per hour.

Three of the process chambers 1024 may be configured to deposit a layerof aluminum or other metal on the substrate. For example, a3,000-angstrom layer of aluminum may be deposited on the substrate at arate of approximately 3,000 angstroms per minute. Such a processgenerally has a sixty second process time, ten seconds of overhead, andan eight second transfer time, yielding a total of 78 second TACT. The78 second TACT corresponds to 48 substrates per hour per chamber, whichfor three chambers yields a total throughput of 138 substrates per hour.

Finally, a process chamber 1024 may be configured to deposit a layer ofmolybdenum on the substrate. For example, a 500-angstrom layer ofmolybdenum may be deposited on the substrate at a rate of approximately2,500 angstroms per minute. Such a process generally has a twelve secondprocess time, ten seconds of overhead, and an eight second transfertime, which yields a TACT of 30 seconds. The 30-second TACT correspondsto a throughput of about 120 substrates per hour.

Upon completion of processing of PVD processes in the second vacuumconveyor module 1020, process substrate exits the module 1020 throughload lock 110 to an atmospheric conveyor 1004, where the substrate ismoved for continued processing. As the total processing throughputdepends upon the slowest processing times, the hybrid CVD/PVD processingsystem 1000 described above has a total throughput of about 120substrates per hour.

Thus embodiments, of a vacuum conveyor system have been provided. Thevacuum conveyor system may utilize conventional vacuum processingchambers and is scalable, segmented, and/or modular. The vacuum conveyorsystem has a small volume that is easier to maintain at vacuum pressuresand contains dedicated substrate handlers for each process chamber.Modular vacuum conveyor systems may be coupled by load locks andindependently maintained at vacuum pressures corresponding to theprocess chambers attached to the respective module. The vacuum conveyorsystem contains a roller drive system that controls the movement ofsubstrates through the system. The roller drive system may be configuredto compensate for sagging of the leading edge of the substrate inunsupported areas between rollers.

Although the above embodiments mainly refer to linear vacuum conveyorsystems, it is contemplated that the vacuum conveyor systems may beparallel with offset axes or linked together non-linearly. For example,the vacuum conveyor system or modules may connect perpendicularly, or belinked together by a vacuum sleeve that provides another angle ofalignment, including a “U” shaped configurations. Furthermore, althoughthe above embodiments have been described mainly with respect to glasssubstrates, it is contemplated that the vacuum conveyor system disclosedherein may be useful for transporting and processing other substrates,for example polymer substrates or semiconductor substrates, that undergoserial vacuum processing.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. Apparatus for conveying a substrate, comprising: a vacuum sleeve; anda plurality of rollers disposed within the vacuum sleeve for supportingand transporting the substrate thereupon, wherein the plurality ofrollers are adapted to simultaneously support the substrate thereupon ata plurality of elevations and wherein a leading edge of the substrate issupported at an elevation above an adjacent one of the plurality ofrollers in the direction of travel.
 2. The apparatus of claim 1, whereinthe plurality of rollers rotate eccentrically about an axis offset withrespect to the center of the rollers.
 3. The apparatus of claim 2,wherein the plurality of rollers are rotationally out of phase withrespect to each other.
 4. The apparatus of claim 2, wherein theplurality of driven rollers are rotationally out of phase by about 180degrees with respect to each other.
 5. The apparatus of claim 2, whereineach of the plurality of driven rollers are rotationally out of phase byabout 90 degrees with respect any adjacent one of the plurality ofdriven rollers.
 6. The apparatus of claim 5, wherein the direction ofthe change of phase from any one of the plurality of rollers to anadjacent one of the plurality of rollers in the direction of travel of asubstrate supported thereupon is opposite to the direction of rotationof the plurality of rollers.
 7. The apparatus of claim 2, wherein atleast one of the plurality of rollers further comprises a plurality ofcylindrical bodies coupled to an axle through an axis of rotation offsetfrom the central axis of the cylindrical bodies.
 8. The apparatus ofclaim 1, wherein the plurality of rollers are eccentrically shaped. 9.The apparatus of claim 8, wherein the plurality of rollers arerotationally out of phase with respect to each other.
 10. The apparatusof claim 8, wherein the plurality of rollers are rotationally out ofphase by about 180 degrees with respect to each other.
 11. The apparatusof claim 8, wherein each of the plurality of rollers are rotationallyout of phase by about 90 degrees with respect any adjacent one of theplurality of rollers.
 12. The apparatus of claim 11, wherein thedirection of the change of phase from any one of the plurality ofrollers to an adjacent one of the plurality of rollers in the directionof travel of a substrate supported thereupon is opposite to thedirection of rotation of the plurality of rollers.
 13. The apparatus ofclaim 8, wherein at least one of the plurality of rollers furthercomprises an axle having a plurality of eccentric bodies coupledthereto, the plurality of eccentric bodies being aligned with respect toeach other.
 14. The apparatus of claim 1, further comprising a pluralityof actuators coupled to the plurality of rollers.
 15. The apparatus ofclaim 14, wherein a first one of the plurality of actuators selectivelyraises the roller disposed beneath a leading edge of the substrate beingtransported thereover.
 16. The apparatus of claim 15, wherein a secondone of the plurality of actuators lowers an adjacent roller proximatethe leading edge of the substrate.
 17. The apparatus of claim 14,wherein a first one of the plurality of actuators selectively lowers theroller subsequent to the roller disposed beneath a leading edge of thesubstrate being transported thereupon.
 18. The apparatus of claim 1,wherein the plurality of rollers are driven.
 19. The apparatus of claim18, wherein the plurality of rollers are driven independently.
 20. Theapparatus of claim 18, wherein a portion of the plurality of rollers aredriven independently with respect to the remaining ones of the pluralityof rollers.
 21. Apparatus for conveying a substrate, comprising: avacuum sleeve; and a plurality of eccentrically-shaped rollers disposedwithin the vacuum sleeve for supporting and transporting the substratethereupon, wherein a first one of the plurality of rollers supports aleading edge of the substrate at an elevation above an adjacent one ofthe plurality of rollers in the direction of travel.
 22. The apparatusof claim 21, wherein the plurality of rollers are driven.
 23. Theapparatus of claim 22, wherein a portion of the plurality of rollers aredriven independently of the remaining ones of the plurality of rollers.24. The apparatus of claim 21, wherein the plurality of rollers arerotationally out of phase with respect to each other.
 25. The apparatusof claim 21, wherein at least one of the plurality of rollers furthercomprises an axle having a plurality of eccentric bodies coupled theretothe plurality of eccentric bodies being aligned with respect to eachother.
 26. Apparatus for conveying a substrate, comprising: a vacuumsleeve; and a plurality of eccentrically-shaped driven rollers disposedwithin the vacuum sleeve for supporting and transporting the substratethereupon, wherein the plurality of eccentrically-shaped driven rollersare rotationally out of phase with respect to each other, and wherein afirst one of the plurality of rollers supports a leading edge of thesubstrate at an elevation above an adjacent one of the plurality ofrollers in the direction of travel.
 27. The apparatus of claim 26,wherein the rollers are independently driven.
 28. The apparatus of claim26, wherein a portion of the plurality of rollers are drivenindependently of the remaining ones of the plurality of rollers.
 29. Theapparatus of claim 26, wherein at least one of the plurality ofeccentrically-shaped driven rollers further comprises an axle having aplurality of eccentric bodies coupled thereto, the plurality ofeccentric bodies being aligned with respect to each other.
 30. A methodfor conveying a substrate, comprising: moving a substrate on a pluralityof rollers in a desired direction; raising a leading edge of thesubstrate with respect to an adjacent roller in the direction of travel;and lowering a second one of the plurality of rollers that is adjacentto a first one of the plurality of rollers that supports the leadingedge of the substrate.
 31. The method of claim 30, further comprisingproviding a plurality of rollers having an eccentric rotational motionthat supports the substrate at a plurality of elevations.
 32. The methodof claim 31, wherein the raising step further comprises supporting thesubstrate on the plurality of rollers such that the leading edge of thesubstrate extends from a first one of the plurality of rollers at afirst elevation that is greater than a second elevation provided by asupport surface of an adjacent second one of the plurality of rollers.